High antibacterial activity of chitosan - molybdenum disulfide nanocomposite

Bacterial infections have evolved as a life-threatening problem afflicting people due to the abuse of antibiotics and emergence of drug-resistant bacteria. Thus developing novel antibacterial materials is an urgent need. Herein, chitosan-MoS₂ (CS-MoS₂) nanocomposite was synthesized through thiol ligand functionalization and chemical modification to achieve more efficient bactericidal activity. CS-MoS₂ exhibited synergistic remarkable bactericidal capability against Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E.coli), where bacterial viabilities were significantly reduced. After treatment with 10 μg/mL of CS-MoS₂, 100% and 98.1% of S. aureus and E.coli cells were killed respectively. A mechanism study revealed that the positively charged CS-MoS₂ could interact with cell membrane, then cause damage to the membrane and cellular constituents by generation of reactive oxygen species (ROS) and glutathione (GSH) oxidation, finally inhibit bacterial growth. The CS-MoS₂ could be an attractive antibacterial agent with improved efficiency and provide more strategies for application of MoS₂.